Yup the male will get alot of bristles, they look like the end of a toliet brush LOL
Check out some of Devs pics she has them but albino ones and they are really cool when they breed.
I got mine at about 3 inch and he had his bristles then. He keeps the tank so clean its amazing! Sinse having him I only waterchange and gravel vac once a week ( they poop ALOT! long dark strings of poop) I have not once had to manually remove algae in that tank and its in my bedroom by the window with lots of light.
Mine lives with 4 female blue guppies and had 2 male blue jap guppies (one now, one was dead when I got home)

that I use for breeding and they get on well. They add a bit of color to the tank and the bristlenose adds a huge amount of character

Do you have a piece of driftwood in there? They need this to munch on and to provide some nutrient that I cant think of right now.
If not then when you get a piece you may want to soak it in buckets till its stops leaching some color in the water before adding it to the tank, and watch the PH carefully, it tends to drop it.